 2008 Pearson Education, Inc. All rights reserved (Optional) Software Engineering Case Study: Starting to Program the Classes of the ATM System Visibility of an object’s attributes and operations – Determined by access specifiers – Data members normally have private visibility – Member functions normally have public visibility – Utility functions normally have private visibility UML Visibility Markers – Placed before an operation or an attribute – Plus sign ( + ) indicates public visibility – Minus sign ( – ) indicates private visibility

 2008 Pearson Education, Inc. All rights reserved. 2 Fig | Class diagram with visibility markers.

 2008 Pearson Education, Inc. All rights reserved. 3 Fig | Class diagram with navigability arrows.

 2008 Pearson Education, Inc. All rights reserved (Optional) Software Engineering Case Study: Starting to Program the Classes of the ATM System (Cont.) Implementing a class from its UML design – Use the name located in the first compartment of a class diagram to define the class in a header file – Use the attributes located in the class’s second compartment to declare the data members – Use the associations described in the class diagram to declare references (or pointers, where appropriate) to other objects Use forward declarations for references to classes (where possible) instead of including full header files – Helps avoid circular includes Preprocessor problem that occurs when header file for class A #include s header file for class B and vice versa – Use the operations located in the class’s third compartment to write the function prototypes of the class’s member functions

 2008 Pearson Education, Inc. All rights reserved. 5 Outline fig09_22.cpp (1 of 1) #ifndef, #define and #endif preprocessor directives help prevent multiple-definition errors Class name is based on the top compartment of the class diagram

 2008 Pearson Education, Inc. All rights reserved. 6 Outline Withdrawal.h (1 of 1) Data members are based on the attributes in the middle compartment of the class diagram

 2008 Pearson Education, Inc. All rights reserved. 7 Outline Withdrawal.h (1 of 1) References are based on the associations in the class diagram #include preprocessor directives for classes of associated objects

 2008 Pearson Education, Inc. All rights reserved. 8 Outline Withdrawal.h (1 of 1) Forward declarations of classes for which this class has references

 2008 Pearson Education, Inc. All rights reserved. 9 Outline Withdrawal.h (1 of 1) Member functions are based on operations in the bottom compartment of the class diagram

 2008 Pearson Education, Inc. All rights reserved. 10 Outline Account.h (1 of 1)